84 INSECT HEARING. 



their eggs. Some indeed have conjectured that it may be 

 merely with intent to explore the nest, and feel for her infant 

 victim, that the insidious Ichneumon thus inserts her antennae; 

 but since the holes are always so deep as to prevent the possibility 

 of her thus reaching the grubs, as they live at the bottom, it 

 seems much more probable, in the opinion of the writer in 

 question, that she employs them as ears to detect any sound 

 of eating or moving from the occupant of the nest. 



Insects are pre-eminently gifted with the sense of smell. No 

 flock of vultures can be directed more unerringly to their re- 

 volting prey by scenting its odours from afar, than are certain 

 Insects, such as Dung-flies and Carrion Beetles, whose corres- 

 ponding office is to assist in ridding the earth of offensive 

 objects. That the sense of smell alone directs the Blow-fly in 

 the deposition of her eggs has been fully proved by the fact of 

 her having, through misguided instinct, been found to lay them 

 on silk wherewith tainted meat has been covered, or upon the 

 ill-odoured Stapelias, a tribe of hot-house plants which in scent 

 greatly resemble it. 



The Butterfly and Bee, with other winged collectors whose 

 more agreeable business lies among sweet odours, are equally 

 quick scented in their detection at distances almost incredible. 

 From a prodigious height, not less, it has been estimated, 

 than sixteen or twenty feet, the former lights down upon its 

 favourite flower ; while the latter wings its way for miles in the 

 exact direction of flowery fields and thymy downs, from which 

 scented breezes bring them invitation. Even when at hand, 

 it is the odour of flowers rather than their appearance by which 

 both Bees and Butterflies would seem to be enticed ; for it was 

 found by M. Huber, that four Bees and a Butterfly were 

 speedily assembled round some honey which he had placed, for 

 experiment, in a window, concealed by shutters only sufficiently 

 open to admit their passage. Availing themselves of this 

 liking for sweets and perception of their distant and invisible 

 presence, moth collectors are in the habit of anointing the 



